The present invention concerns a device for switching electromagnetic equipment, especially for switching a direct-current brake for a three-phase motors with a switching contact and with a rectifier with integrated protective circuitry.
Brakes of this genus can be connected to motor terminals. A device for switching a direct-current brake in a three-phase motor is known from German 3 249 877 C2. It is connected by phase conductors to a three-phase network with a single-phase braking circuit that connects the network to one phase of the motor and contains two subsidiary circuits, one with a rectifier and the other with a free-wheeling diode, with an operations contact, and with a brake contact that diverts the braking circuit, whereby one contact controls the other by way of auxiliary switching equipment. The operations contact has engagement switches in the first-and-second phase conductor and a disengagement switch in the braking circuit. The second subsidiary circuit is connected to the third-phase conductor, which lacks a switch. The brake contact has an engagement switch in the first-phase conductor and a disengagement switch in the braking circuit and an auxiliary engagement switch that controls the operations contact. Only the brake contact can be engaged and disengaged from outside.
There are drawbacks to this device. The lines that connect it to the motor terminals are long and it takes up a lot of space.